There are continuous attempts made to enhance the maneuverability and stability of vehicles.
For example, variable track axles are known to facilitate the use of vehicles in different environments, adjustment of vehicle aerodynamics at different speeds or adjustment of vehicle stability at different driving conditions. There are also known three-wheeled vehicles with a tiltable frame for increasing the driving capabilities of the vehicle at higher speeds.
For example, a U.S. Pat. No. 6,902,022 presents a tractor having a convertible front end and a variable track width. The tractor has a steerable, interchangeable front wheel assembly and an adjustable rear track width. The removable front wheels assembly allows easy conversion between a single wheel and a two wheel front wheel assembly. In combination with the interchangeable front wheel assembly, the adjustable rear wheel track width allows changing of the turning radius of the tractor. The configuration is clearly directed to large and heavy vehicles of wide turning radius, the turning radius being adjustable by the width of the rear track.
In turn, a PCT application No. WO9950128 presents a short, narrow motor vehicle having a parallelogram linkage at each side, to which the front or rear wheels are connected, enabling displacement of wheels in a coordinated way. The vehicle is steered via front wheels and the steering mechanism is configured to enable the front wheels to be steered irrespective of the extent of their displacement, although in the retracted position the range of turn is limited. The rear wheels are non-steerable.
A U.S. Pat. No. 4,717,164 presents a road vehicle comprising a rotatable chassis section rotatable with respect to a fixed chassis section, a steering mechanism and a banking mechanism for automatically rotating the rotatable chassis section about the horizontal axis whenever the steering mechanism is actuated to steer the vehicle. Such vehicle may become unstable at low speed and taking a sharp turn.
A U.S. Pat. No. 5,927,424 presents a self-balancing vehicle with at least three wheels: one steerable and two non-steerable, wherein at least one section of the vehicle is tiltable about the longitudinal axis of the vehicle via a power-assisted tilt element. The tilt is produced as a function of a sensor measurement of the magnitude and/or the direction of a change in direction of the steerable wheel during travel. The vehicle has limited steering capabilities due to only one steerable wheel.
A US patent application No. US20060170171 presents a vehicle with a tiltable chassis and front wheels adapted to move transverse to their axes of rotation in order to tilt said chassis. The front wheels have variable track width, configured to be set to wide track for low speeds and to narrow track for high speeds, so as to allow tilting at high speeds. The vehicle is tiltable by tilting the whole chassis together with all wheels.
The disadvantage of the above-mentioned vehicles is that they occupy relatively lot of space when parked and/or have a limited steering capabilities at low speeds due to wide track or low range of turn.
The aim of the present invention is to provide a vehicle which can be driven in an easy and stable manner at high speeds, while allowing high maneuvering capabilities at low speeds and requiring little parking space.